Disc drives are common data storage systems. A typical disc drive includes a rigid housing having a base deck that encloses a variety of disc drive components. The components include one or more discs having data surfaces that are coated with a medium for storage of digital information in a plurality of circular, concentric data tracks. The discs are mounted on a spindle motor that causes the discs to spin and the data surfaces of the discs to pass under aerodynamic bearing head sliders. The sliders, supported on suspension arms that move across the disc by an actuator mechanism, carry transducers, which write information to and read information from the data surfaces of the discs.
A flexible circuit assembly electrically connects the read/write elements on the disc head slider and the arm electronics on the actuator mechanism to a printed circuit board (PCB) that interfaces with a host computer. The flexible circuit assembly includes a flexible cable that allows pivotal movement of the actuator mechanism during operation. The flexible cable includes electrical traces supported by a polymeric carrier material.
Resonance in the flexible cable continues to be a common problem in data storage systems. When a data storage system is engaged in a data seeking process, the flexible cable moves together with the actuator mechanism at a connected end. As a result, the motion/vibration/resonance associated with the flexible cable can be large enough to cause functional failure for the system, e.g. the slider is unable to settle out above the commanded track as rapidly as required. As each new generation of data storage system demands more recorded tracks per inch, attenuating or reducing the flex resonance becomes more important. Recently many flexible circuit designs have incorporated dampers adhered to the flexible cable to absorb some of the energy associated with vibration in the flex cable. However, these dampers do not solve the problems related to variation in frequency of vibrations.
Embodiments of the present invention provide solutions to these and other problems, and offer other advantages over the prior art.